The Safety Of Creatine


Within the past five years creatine has emerged as the top selling nutritional supplement in the world. Creatine sales totaled over 400 million dollars last year alone! There is good reason for the increase in creatine sales: it is safe and it works! There are a great number of studies touting its effectiveness. However, over the past few years some have questioned creatine's safety. This has led to a large-scale spread of misinformation among the public about creatine.

Some people have claimed creatine causes problems, from muscle cramps and dehydration to kidney failure. Due to misinformation, some coaches and schools have forbidden creatine usage and teams like the Tampa Bay Buccaneers do not even allow it in their locker room. The National Collegiate Athletic Association (NCAA) has recently banned the distribution of creatine by colleges to its players and is even considering banning the use of creatine. The time has come to stop this spread of misinformation about creatine so people can make intelligent decisions about based on scientific evidence, not opinion.

What Is Creatine?

Creatine is a combination of three amino acids: glycine, arginine, and methionine. It is produced by the liver and can be found in foods such as meat and fish, usually at a concentration of four grams per kilogram of meat. Most people ingest about one gram of creatine per day and the body produces about one gram of creatine per day on its own.

When creatine is taken in the form of a supplement it has several benefits for hard training athletes. After creatine is ingested it bonds with a phosphate group to form creatine phosphate (CP). CP can then donate a phosphate molecule to adenosine di-phosphate (ADP) to form adenosine tri-phosphate (ATP). ATP is the energy currency of cells, is used to drive almost all cellular functions, and is a crucial molecule in muscular contraction. Supplementing with creatine increases the body's ATP production thus enhancing performance and decreasing fatigue in intense, short duration activities such as weightlifting and sprinting (1).

Another benefit of creatine to athletes is its ability to hydrate muscle cells. Creatine pulls fluid from outside the muscle cells into the cells. The increase in water retention by the cells also causes more ions, such as nitrogen, to be pulled into the cell, which increases muscle protein synthesis. This increase in muscle protein synthesis allows athletes to recover from exercise faster and in turn grow more muscle (5). One can see the benefit of creatine supplementation to athletes who engage in high intensity sports that require quick bursts of energy or athletes who want to improve their strength and speed.

Long Term Side Effects?

Opponents of creatine supplementation cite several reasons for not using creatine, The NCAA recently banned the distribution of creatine by colleges to their athletes "because of the lack of long-term studies on possible side effects (6)." They claim since creatine is a relatively new supplement there is no way to tell whether or not it has any long-term side effects.

Creatine has been around for quite some time though. There actually have been studies conducted on creatine supplementation, which concluded that long term creatine use has no side effects (8 and 9). Steven Scott Plisk, director of sports conditioning at Yale University says, "it has been used in the United Kingdom since the early 1980's without any problems... if creatine caused long-term side effects, there would be indicators in the shorter studies. With anabolic steroids, you see some signs in the short term that warn you about what's coming in the long term, and you don't see any of that with creatine (7)."

Cramping And Dehydration?

Some coaches claim creatine has caused dehydration and muscle cramps among their athletes. Ross Bailey, head athletic trainer at Texas Christian University (TCU), believes creatine is the cause of frequent cramping and pulled hamstrings among athletes at TCU. "We have no scientific evidence, but the use of creatine is the only thing that has changed" says Bailey (4). There is no scientific evidence to support his claims, as he states. The causes of muscle cramps and dehydration are likely both due to inadequate water consumption, not creatine supplementation. There IS scientific evidence to support creatine not causing dehydration or muscle cramps among college athletes, though.

Two similar studies on creatine's effects were conducted upon college athletes by the American Alliance for Health, Physical Education, Recreation and Dance (AAHPERD) which demonstrated creatine safety. One study looked at the side effects associated with creatine supplementation on Division I-A football players during 3-a-day practices. The other study was almost exactly the same, the only difference being Division I-A baseball players were studied during fall collegiate baseball.

Both studies concluded that there were "no perceived side-effects or health-status problems associated with creatine supplementation" in the athletes during the time period in which they were examined (2 and 3). Opponents of creatine supplementation sometimes try to discredit studies such as these by stating that they are only looking at a short period of time and cannot determine how creatine supplementation affects dehydration and muscle cramping in athletes over a long period of time. There is scientific evidence to counter that argument. A recent study examined the relationship between adverse health effects and long-term creatine supplementation in athletes. The researchers concluded that there "were no differences in incidences of cramps, muscle injury, or side effects between athletes and controls (9)."

Kidney Problems?

Opponents of creatine supplementation also like to state creatine is hard on the kidneys and can cause kidney damage with long term use. Creatine's waste product is creatinine, which is excreted by the kidneys, and creatinine is used as a marker of kidney dysfunction. Since creatine supplementation increases creatinine levels, it is easy to speculate that creatine may cause kidney damage since it increases a marker of kidney dysfunction.

However, creatinine is merely a marker of kidney dysfunction, cause and effect has not been established. There is no scientific evidence to support the hypothesis that creatine is damaging to the kidneys. There is scientific evidence to the contrary, however. A study examined whether or not oral creatine supplementation affected the kidneys of athletes over short, medium, and longterm periods of supplementation.

The researchers concluded that creatine caused "no detrimental effects on athletes' kidney functions from short, medium, or long-term use of this supplement (8)." Jeff Volek, a doctoral student at the Center for Sports Medicine at Pennsylvania State University, recently completed a study that found no negative side effects to creatine use states, "because it is a naturally occurring compound, side effects are not as likely... and it has been proven to be readily handled by the kidneys (4)".

There have been some concerns that creatine may exacerbate kidney problems in individuals with pre-existing renal dysfunction. One case report of acute renal failure was reported in a 20-year-old man taking 20 gm/day of creatine for a period of four weeks (more than the recommended dose). However, a study examining effects of creatine supplementation on rats with pre-existing renal failure concluded that creatine caused no additional impairment of kidney function in the animals (9). Research clearly shows creatine supplementation is safe in individuals with normal kidney function. Further study is needed before recommendations can be made for individuals with renal failure.

Creatine Therapy?

In addition to being a safe supplement, creatine may also provide a therapeutic effect for several neuronal disorders including amyotrophic lateral sclerosis, Huntington's disease, Parkinson's disease, and traumatic brain injury, such as a stroke. Since caspasemediated (caspases are proteolytic enzymes) pathways are shared functional mechanistic components in these diseases, a new study investigated the effect of creatine supplementation on caspase activity after a stroke.

The researchers found creatine supplementation significantly reduced caspase activity and "resulted in a remarkable reduction in ischemic brain infarction and neuroprotection after cerebral ischemia in mice (11) ". Researchers also hypothesized creatine may exert its protective effect by preventing ischemia - mediated cerebral ATP depletion, through preservation of cellular energy status.

Amyotrophic lateral sclerosis (ALS) is characterized by progressive degeneration of motor neurons, resulting in weakening and atrophy of skeletal muscles. In patients with this condition, creatine supplementation has been shown to increase muscle contractility and improve neuronal function. Creatine may also help stabilize mitochondria) dysfunction, which plays a major role in the pathogenesis of ALS (11). Clinical trials are currently underway to determine creatine's effectiveness in treating this disorder.

Unfair Competitive Advantage?

Some creatine opponents claim creatine may give athletes an unfair advantage. Creatine is available to anyone and is very affordable (a 200+ day supply can be found for as little as $20 on several websites), though. Using the same notion that creatine may provide an unfair advantage to athletes supplementing with it one would have to consider whether vitamins provide an unfair advantage to athletes who use those. Should athletes thus be discouraged from supplementing with vitamins? Certainly not.

Creatine should not be treated differently. Unfortunately, claims of unfair advantages were involved in the NCAAs decision to ban the distribution of creatine. Claims were made that there are a number of schools that have more money than others and can provide items others can't (6).

Conclusion

Over the past few years creatine has emerged as an effective and safe supplement that benefits athletes who are looking to increase strength, size, and power. Its safety and effectiveness has been supported in numerous peer-reviewed studies and many experts in the field of sports nutrition. Creatine has also shown to potentially have therapeutic effects on neuronal disorders. It's unfortunate that unfounded statements regarding creatine's safety have caused the spread of misinformation throughout the country and have possibly even led the NCAA to ban the distribution of creatine. Hopefully, in the years to come, misinformation will be replaced by scientific reasoning.